Filter replace advice for community pool

[pjones2127]

Hello everyone. I'm new to this forum and like most people, I'm here looking for some sound advice. I'm board president of the Camelot Recreation Association, a local community pool in Huntsville, AL. Camelot is an 25 meter 8-lane pool with a 12'dive well. The faclity was constructed in 1972. We have a single huge tank-type sand filter. I'm not exactly sure of the capacity, but it is very large, about 6' high and about as wide.

This year we've been getting a lot of sand in the pool as a result of backwashing. I'm told this is due to a corroded pipe inside the filter that will need to be replaced. I have an estimate for work to refurbish the filter for about $8000. The work will involve cutting the tank open with a torch, welding in new guts and replacing the sand.

Today, I was talking with a friend of mine (Bill) who services pools. Bill's advice is to get rid of the old steel tank filter and replace it with an array of 4 or 5 smaller, commercial-sized, off the shelf sand filters. Bill says I can do this for about half what we would spend repairing the single filter, and the smaller filters are more easily and economically maintained.

My question: What are the advantages of a filter array as opposed to a single large filter? Should we take Bill's advice and get away from the single filter system?

[dynamictiger]

Sorry for the late reply, I have only just joined this forum.

For commercial pools the rules are slightly different than domestic pools. The minimum sand bed depth should be 900 mm I think this is approximately 36 inches.

The flow rate across the sand bed should be 24 m3/m2/hr. This will result in a significantly larger sand area than a domestic filter system as they operate between 42 and 65 m3/m2/hr. When you think this through it is logical, a domestic pool is subject to a small irregular load usually of the same group of people. A commercial pool is subject to varying loads some quite large with different people all the time.

My opinion for what it is worth is that Bill is probably not correct with the statement the costs to replace will be lower than repair costs, if the correct filters are selected and installed. However I tend to agree with Bill that spending $8k repairing a steel vessel is probably not a wise investment. Usually on slicing the vessel it is quite possible other damage may preclude it returning to service.

Sorry this is in metric, I just find it simpler to think in metric.

HTH